Apparatus for weft supply control

ABSTRACT

Method of and apparatus for controlling the weft supply into the weft inserters of travelling-wave shedding weaving machines wherein weft supply units follow an endless path which is partly common with an endless path of the weft inserters. A decrease in tension of weft threads being supplied is scanned and transformed into an electric signal adapted to give an impulse for stopping the drive of the weaving machine before an incorrectly weftfilled inserter has entered the warp shed.

United States "Patent Musil et al.

[ Jan. 21, 1975 APPARATUS FOR WEFT SUPPLY CONTROL [75] Inventors: Peter Musil; Frantisek Bucil; Karel Spatenka; Miroslav Rysavy, all of Usti Nad Orlici, Czechoslovakia [73] Assignce: Vyzkumny Ustav Bavlnarsky, Usti nad Orlici, Czechoslovakia [22] Filed: June 4, 1973 [21] Appl. No.: 366,640

[30] Foreign Application Priority Data June 12, 1972 Czechoslovakia 4058-72 [52] US. Cl 139/12, 139/224 A, 139/336.4 [51] Int. Cl. D03d 47/26, D03d 51/34 [58] Field of Search 139/12, 13, 16, 224, 336,

[56] References Cited UNITED STATES PATENTS Cvach 139/353 Svaty et al. 139/370 Jekl et a1. 139/12 Primary ExaminerHenry S. .laudon [57] ABSTRACT Method of and apparatus for controlling the weft sup ply into the weft inserters of travelling-wave shedding weaving machines wherein weft supply units follow an endless path which is partly common with an endless path of the weft inserters. A decrease in tension of weft threads being supplied is scanned and transformed into an electric signal adapted to give an impulse for stopping the drive of the weaving machine before an incorrectly weft-filled inserter has entered the warp shed.

6 Claims, 6 Drawing Figures PATEHTED JANZ] I975 SHEET 1 BF 4 FIG.

PATENIED m2! i915 SHEET 2 OF 4 FIG. 5

APPARATUS FOR WEFT SUPPLY CONTROL The present invention relates to a method of and an apparatus for controlling the weft supply to weft inserters on travelling-wave shedding weaving machines.

The supplying of weft thread to weft inserters on a travelling-wave shedding weaving machine is accomplished by means of weft supply units following an endless path which is common with a part of the path of the weft inserters. While the path of the weft inserters has substantially an oval configuration, the path of the weft supply units can be either circular or oval. The weft supply unit furnishes the inserters with an appropriate weft thread length corresponding to the width of the fabric being woven. In case of a failure in the weft supply process, such as, for example, a weft thread breakage, or in case of a failure on a weft supply unit, the weft inserter may be furnished with a shorter weft length which is then inserted into the shed. The result is a fault in the fabric which, in view of the operating principles of travelling-wave shedding machines can not be corrected. The machine operator will not perceive such a fault until several succeeding wefts have been picked. With the relatively high weaving speeds of operation used in these machine types in view, any visual weft supply control by the operator is out of the question.

Hitherto practised weft supply processes have either not been controlled at all, or have been controlled by means of imperfect devices. Such a device comprises, as a rule, two weft metering wheels engaging each other mounted on a weft supply unit. The weft thread to be supplied is conveyed through the nip between said wheels and frictionally rotates them. One of said weft metering wheels is coupled via a gear with a control rod which remains retracted during the correct weft supplying process. The thus retracted control rod will not engage a machine stop controlling switch provided on the frame of the weft supplying device and thus the switch remains open. On the contrary, in case of a weft supply failure, such as a weft breakage or the like, the weft metering wheels fail to rotate so that the control rod is not retracted and thus engages the switch; the switch now closes the circuit which transmits an impulse to stop the machine. An insufficiency of such a device consists in that it depends upon friction between the weft thread and the weft metering wheels. Thus in case of variations in such friction, the control rod will not be retracted at all, or will be retracted on insufficient distance even when the weft supply proceeds correctly.

It is an object of the invention to eliminate the drawbacks of the prior art as hereinbefore set forth and to provide a method of controlling the supplying of weft into weft inserters. In the method, according to the invention, any decrease in tension of the weft threads being supplied is monitored and transformed into an electric signal for stopping the drive of the weaving machine at the latest before the incorrectly weft-filled inserter has entered the warp shed.

In the apparatus of the invention for carrying out the afore-described method the weft supply units are provided with detectors designed to detect any decrease in tension of the weft thread being supplied. The detectors have movable control elements of which the motion path, when they are deflected, is directed through a scanning region of at least one scanner for scanning a signal from the detector. Said one signal scanner is supported by the weaving machine frame within a section of the path of the weft supply units, such section extending between the point where the weft supply process is finished and the point where the weft supply units and the weft inserters diverge from each other. The signal scanner is coupled with a control device for controlling the weaving machine drive.

The tension detector is constituted by a two-armed lever supported to oscillate transversely to the weft thread being supplied, and provided on one of its arms with a weft guide and on the other arm with a control element, said two-armed lever being loaded by a weft deflecting spring acting in the crosswise direction relative to the path of the weft thread supplied.

In accordance with some other features of the apparatus, the control elements are electrically connected to an electrically conductive rail along which the weft supply units are adapted to move and which is connected to one pole of a power source, while an electrically conductive trolley extending parallel with said rail is arranged on the weaving machine frame within the reach of control element deflection, said trolley being electrically insulated from the frame and connected via a control system with the second pole of said power source. a

On the weft supply unit there is pivotally arranged an arresting lock serving to arrest the two-armed lever.

The control element can be embodied as a shutter.

The main merit of the present invention resides in that the weft supply control is continuously carried out during the operating cycle of the weft supply units and that in case of a failure the respective weft supply unit will stop at a place where the failure can be easily corrected.

In order that the invention be better understood and carried into practice, some preferred embodiments thereof will be now described with reference to the somewhat schematic accompanying drawings which, however, are not intended to limit, in any way, the scope of the invention. In the drawings:

FIG. 1 is a schematic view illustrating the fundamental principle of the weft supply to the weft inserters;

FIG. 2 is a perspective, partly sectional view of a mechanical weft tension detector;

FIG. 3 is fragmentary plan view showing schematically the weft supplying device together with the weft supply units and the weft inserter path;

FIG. 4 is a schematic view in plan of a first modified embodiment of the weft supplying device;

FIG. 5 is a schematic view in plan of a second modifled embodiment of the weft supplying device; and

FIG. 6 is a perspective detail view of a roll rolling along a conductive rail in the embodiment shown in FIG. 5.

Discussing now the drawings in detail, and particularly FIG. 1 thereof, it can be seen that the weft thread 6 to be supplied is paid off from a reserve package 7 and is guided by guide eyelets 18a, 18b via a thread brake 19 to a guide eyelet 20 of a weft tension decrease detector 12 and finally via guide eyelets 18c, 18d into a weft supply unit 5 where the weft thread is retained by a weft thread clamp 21. From the weft thread clamp 21 the weft thread 6 is conveyed to a weft inserter 3 and its length is metered by a weft metering mechanism (not shown) of the weft supply unit 5. The weft tension decrease detector 12 is embodied as a two-armed lever 24 adapted to oscillate about a pivot 23 provided on the weft supply unit 5. One arm 24a of the two-armed lever 24 is provided at its extremity with a guide eyelet 20 for the weft thread 6 while the second arm 24b thereof is embodied as a shutter 11 designed as an element for controlling a signal scanner, such as for instance. of the photoelectric, capacitive or the like type. The pivot 23 moreover supports an end of a weft deflecting spring 22 the other end of which is secured on the arm 24b. A weft tension decrease detector 12 is provided on each weft supply unit 5.

An actual embodiment of the mechanical weft tension decrease detector 12 is illustrated in FIG. 2. It consists of a protective housing 25 provided with a web 26 by means of which it can be secured to the weft supply unit 5, the web being provided with a slot for bolts. The two-armed lever 24 is fixedly attached by a bolt 35 to a disc 27 rotatably supported on the pivot 23 in the housing 25. The disc 27 is provided with a hub having an extension 28 on which the inner end of the spiral spring 22 is fixed, while the outer end of the latter is anchored in a slot 29 of a drum 30 having a graduated scale 31. A portion of the scale 31 can be read off through a window 39 cut out in the top wall of the housing 25. From said top wall of the housing 25 there projects a shank 32 having a notch for the reception of a screw driver, the shank being connected with the axle of the drum 30. A strap plate 33 attached to the top wall of the housing 25 by a screw bears against the drum 30. The extremity of the arm 24a of the twoarmed lever 24 is provided with the guide eyelet disposed between the two guide eyelets 18b and 18c. All the three eyelets 18b, 20, 18c are substantially coaxial and guide the weft thread 6 being supplied. The second arm 24b of the two-armed lever 24 in the form of the shutter 11 is visible through a lateral opening 9 in the housing 25. Further, the housing carries an arresting lock 38 pivotally mounted at 46 and designed to limit the outswing of the shutter 11 for assembling and testing purposes. A lining 37 of a resilient material, such as, for instance, foamed polystyrene, is fixed to the inner rear wall of the housing 25 at the place thereof where the deflected arm 24a bears against said wall so as to cushion the impacts of said arm. The degree of bias of the deflecting spiral spring 22 is adjusted by turning the drum together with the scale 31 relative to an index line 36 on the top wall of the housing 25. The selected angular position of the drum 30 will be set by means of a strap plate 33 and the screw 34.

FIG. 3 shows an oval path 4 followed by the weft inserters 3 passing through the shed 2 and then returning again into the weft supplying device. The weft supplying device comprises a plurality of weft supply units 5 uniformly along their path, the distances therebetween corresponding to those between the weft inserters 3. For the sake of clarity, only a small number of the weft supply units 5 is shown. The weft supply units 5 follow an oval path of which part is common with the path of the weft inserters 3. A guideway 8 extending externally around the path of the weft supply units 5 slidingly supports reserve packages 7 of the weft thread 6 for movement therealong, each of said packages 7 being designed for one respective weft supply unit 5. The weft thread 6 is supplied from the package 7 via guide eyelet 18a, guide eyelet 18b, guide eyelet 20 of the mechanical weft tension decrease detector 12 and therefrom through the guide eyelet 18c (FIG. 1) to the weft inserter 3.

In an operating zone 17 of the path 4 there is provided a contactless scanner 13 designed to pick up a signal issued by deflecting the arm 24b, i.e., the shutter 11 of the mechanical detector 12, in such a manner that the path of the deflected arm 24b, i.e., the shutter 11, extends either above or through a recess provided in the scanner 13, which means that said path interferes with the scanning zone of the scanner 13. In the embodiment shown, the scanner 13 is of a photoelectric cell type, the shutter l 1 provided on the arm 24b being designed to prevent a light beam from striking the photoelectric cell of the scanner 13. The scanner 13 is connected to an amplifier 14 which in turn is connected to a control device 15 to control the weaving machine drive 16. The operating zone 17 of the path 4 is disposed at the end portion of the common section of the path 4, i.e., where the path 4 of the weft inserters 3 and the path of the weft supply units 5 diverge from each other.

FIG. 4 illustrates a first alternative embodiment of the invention. In such embodiment a plurality of contactless scanners I3 is provided along the path 4, each of them being separately connected to the amplifier I4 and the weaving machine drive control device 15. Since the circuitry connecting the aforementioned elements is known per se, a detailed wiring diagram is not necessary.

FIGS. 5 and 6 illustrate a second embodiment of the apparatus. In such embodiment the weft supply units 5 are carried by rolls 41 rolling along an oval electrically conductive rail way 40. Externally and in parallel with the electrically conductive rail way 40 there extends an electrically conductive trolley 43 which is electrically connected via a conductor 42 with the electrically conductive two-armed lever 24 of the mechanical weft tension decrease detector 12. The conductive rail 40 is connected to the positive pole of a power source 45. The electrically conductive trolley 43 is electrically connected to the amplifier 14 which is connected in turn to the negative pole of the power source 45. The amplifier 14 is in turn connected to the control device 15 controlling the drive 16 of the weaving machine.

In accordance with further alternative embodiment (not shown), a knife-blade or a similar switch is interposed in the circuit controlling the drive 16 of the weaving machine so that it interferes with the path of and is operated by the projected arm 24b of the twoarmed lever 24 of the weft tension decrease detector 12.

From the contactless scanners, photoelectric, capacitive, inductive and the like scanners can be used.

The two-armed lever 24 constituting the mechanical detector can be replaced, e.g., by a displaceable springloaded weft thread deflecting element.

In the process of supplying weft thread 6 into the weft inserters 3 the weft supply units 5 follow their endless path in the direction S (FIG. 3). During the supply of the weft thread 6 into the weft inserter 3, the taut weft section between the guide eyelets 18b and 18c maintains the shutter 11 continuously under tension imparted by the deflectin spring 22 so that the guide eyelets 18b and are substantially coaxial with the guide eyelet 20 on the arm 24a (FIGS. 1 and 2). If, however, a failure, such as, for example a weft breakage or a failure in the weft supplying system of the unit, takes place, the tension of the weft thread 6 drops so that the two-armed lever 24 (i.e., the shutter 11 on its arm 24b) of the weft tension decrease detector 12 will be deflected, due to the action of the deflecting spring 22, as indicated in FIGS. 1 and 2 in dash-lines. As soon as a defective weft supply unit 5 approaches the photoelectric scanner 13, the deflected shutter 11 will interrupt the light beam issued from a source (not shown). In this way the mechanical signal from the detector 12 is transformed into an electric one which, after having been amplified in the amplifier 14, reaches the control device 15 and thus causes the weaving machine drive 16 to stop. The stoppage takes place at the instant the defective weft supply unit 5 has reached the operating zone 17 of the path 4, which means after the respective defective weft supply unit 5 has finished its complete operating cycle. In this zone 17 the failure will be repaired by the operator and the weaving machine restarted.

In the first alternative embodiment (FIG. 4) comprising a plurality of signal scanners 13, a machine stop impulse can be issued immediately after a failure if any of the weft supply units 5 has been ascertained, i.e., be fore the respective unit has finished its operating cycle. It is also possible to store a signal of the detector 12 provoked by the failure, and not to issue the machine stop impulse until the defective weft supply unit 5 has reached the operating zone 17 of the path 4.

In case of a failure in the weft supply unit 5, in the second alternative embodiment shown in FIG. 5, the arm 24b of the weft tension decrease detector 12 is deflected and comes into electric contact with the conductive trolley 43. In this way the electrical circuit comprising the positive pole of the power source 45, the conductive rail 40, the rolls 41, the conductor 42, the arm 24b, the conductive trolley 43, the amplifier l4 and the negative pole of the power source 45, is closed. The thus generated signal amplified by the amplifier 14 is conveyed to the control device 15 which will then stop the drive 16 of the weaving machine.

The non-illustrated arrangement equipped with a knife-blade or like switch to be actuated by the outstanding arm 24b of the weft tension decrease detector 12 operates in the same manner.

In the case of a failure in the weft supply process, the drive of the weaving machine has to be stopped, at any rate, before the incorrectly spooled weft inserter 3 has entered the warp shed 2, i.e., when the operator is still in a position to furnish, e.g., manually, the weft inserter 3 with the necessary length of weft. In the embodiment shown in FIG. 3, this condition is met in that the scanner 13 is arranged on the weaving machine frame within a section of path of the weft supply units 5, which section is defined by the point in which the weft supply process is finished, and the point in which the weft supply units 5 and the weft inserters 3 diverge from each other, each of them then following their own path. In the embodiment according to FIG. 4 the last downstream scanner 13 relative to the direction of the motion S of the weft supply units 5 and the weft inserters 3, had to be located at the latter point.

Although the invention is illustrated and described with reference to a plurality of preferred embodiments thereof, it is to be expressly understood that it is in no way limited to the disclosure of such a plurality of preferred embodiments, but is capable of numerous modifications within the scope of the appended claims.

What is claimed is:

1. Apparatus for controlling the weft supply into the weft inserters of a travelling-wave warp shedding weaving machine wherein weft supply units follow an endless path which is partly common with an endless path of the weft inserters, comprising detectors mounted on the weft thread being supplied, said detectors having (movable) deflectable control means, a scanner for scanning a signal from the detector the path of motion of said control means, when deflected, being directed through a scanning zone of the scanner for scanning a signal from the detector, said scanner being supported by the weaving machine frame within a section of the path of the weft supply units lying between the point where the weft supply units and the weft inserters diverge from each other, and a drive for the weaving machine, a control device for controlling the weaving machine drive, and means operatively connecting the scanner to the control device so as to stop the drive of the weaving machine before an incorrectly weft-filled inserter has entered the warp shed.

2. Apparatus as claimed in claim 1, wherein the detector comprises two-armed lever supported to oscillate across the weft thread being supplied, the lever being provided on one of its arm with a weft guide and on the other arm with said control means, said twoarmed lever being loaded by a weft deflecting spring acting in the cross-wise direction relative to that of the weft thread being supplied whereby to deflect the weft thread.

3. Apparatus as claimed in claim 2 comprising an arresting lock pivotally arranged on the weft supply unit for arresting the two-armed lever.

4. Apparatus as claimed in claim 2, wherein said control means is in the form of a shutter.

5. Apparatus as claimed in claim 2, comprising an electrically conductive rail along which the weft supply units are adapted to move said rail being connected to one pole of a power source, the control means being electrically connected to said rail, an electrically conductive trolley extending in parallel with said rail mounted on the weaving machine frame within the reach of deflecting of said control means, said trolley being electrically insulated from said frame and connected via said control device for the machine with the second pole of said power source.

6. Apparatus as claimed in claim 5, comprising an arresting lock pivotally arranged on the weft supply unit for arresting the two-armed lever. 

1. Apparatus for controlling the weft supply into the weft inserters of a travelling-wave warp shedding weaving machine wherein weft supply units follow an endless path which is partly common with an endless path of the weft inserters, comprising detectors mounted on the weft thread being supplied, said detectors having (movable) deflectable control means, a scanner for scanning a signal from the detector the path of motion of said control means, when deflected, being directed through a scanning zone of the scanner for scanning a signal from the detector, said scanner being supported by the weaving machine frame within a section of the path of the weft supply units lying between the point where the weft supply units and the weft inserters diverge from each other, and a drive for the weaving machine, a control device for controlling the weaving machine drive, and means operatively connecting the scanner to the control device so as to stop the drive of the weaving machine before an incorrectly weft-filled inserter has entered the warp shed.
 2. Apparatus as claimed in claim 1, wherein the detector comprises two-armed lever supported to oscillate across the weft thread being sUpplied, the lever being provided on one of its arm with a weft guide and on the other arm with said control means, said two-armed lever being loaded by a weft deflecting spring acting in the cross-wise direction relative to that of the weft thread being supplied whereby to deflect the weft thread.
 3. Apparatus as claimed in claim 2 comprising an arresting lock pivotally arranged on the weft supply unit for arresting the two-armed lever.
 4. Apparatus as claimed in claim 2, wherein said control means is in the form of a shutter.
 5. Apparatus as claimed in claim 2, comprising an electrically conductive rail along which the weft supply units are adapted to move said rail being connected to one pole of a power source, the control means being electrically connected to said rail, an electrically conductive trolley extending in parallel with said rail mounted on the weaving machine frame within the reach of deflecting of said control means, said trolley being electrically insulated from said frame and connected via said control device for the machine with the second pole of said power source.
 6. Apparatus as claimed in claim 5, comprising an arresting lock pivotally arranged on the weft supply unit for arresting the two-armed lever. 